Superplastic deformation mechanism of an Al-Mg-Li alloy by high resolution surface studies

Abstract Due to a lack of direct observation of grains deformation and sliding, the fundamental mechanisms of superplasticity are still widely disputed. To accurately understand the superplastic deformation mechanism, the grains movement behavior of an Al-Mg-Li alloy with fine equiaxed structure during superplastic deformation was studied by surface girds created using focused ion beam (FIB). The results show that the grain boundary sliding is the primary deformation mechanism, its contribution is 34.8%–51.6%, intragranular dislocation slip plays an accommodating role.